SELECT 
  cscart_product_descriptions.product_id, 
  cscart_product_descriptions.short_description, 
  IF(
    cscart_product_descriptions.short_description = '' 
    OR cscart_product_descriptions.short_description IS NULL, 
    cscart_product_descriptions.full_description, 
    ''
  ) AS full_description 
FROM 
  cscart_product_descriptions 
WHERE 
  cscart_product_descriptions.product_id IN (
    86360, 86887, 90844, 92383, 92384, 92385, 
    92386, 92387, 92388, 92389, 84242, 
    84289, 88584, 91889, 91890, 91891, 
    92333, 92334, 92335, 92336, 82555, 
    85581, 86888, 82553, 88389, 88391, 
    92365, 82391, 82554, 86890, 87789, 
    87795, 91864, 88388, 92374, 82559, 
    85576, 85584, 86352, 88095, 82428, 
    82552, 82564, 82568, 82572, 85572, 
    88392, 91976
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00047

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "21.63"
    },
    "table": {
      "table_name": "cscart_product_descriptions",
      "access_type": "range",
      "possible_keys": [
        "PRIMARY",
        "product_id"
      ],
      "key": "PRIMARY",
      "used_key_parts": [
        "product_id",
        "lang_code"
      ],
      "key_length": "9",
      "rows_examined_per_scan": 48,
      "rows_produced_per_join": 48,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "16.83",
        "eval_cost": "4.80",
        "prefix_cost": "21.63",
        "data_read_per_join": "183K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`nuie_scalesta_net`.`cscart_product_descriptions`.`product_id` in (86360,86887,90844,92383,92384,92385,92386,92387,92388,92389,84242,84289,88584,91889,91890,91891,92333,92334,92335,92336,82555,85581,86888,82553,88389,88391,92365,82391,82554,86890,87789,87795,91864,88388,92374,82559,85576,85584,86352,88095,82428,82552,82564,82568,82572,85572,88392,91976)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}